Drip chamber with hydrophobic interior surface

ABSTRACT

A drip chamber for an infusion tube, including: a first end including a drip tube; a second end including an exit port; and a wall connecting the first and second ends and including an interior surface with a hydrophobic portion. The drip chamber includes a space enclosed by the interior wall and the first and second ends. The hydrophobic portion of the interior surface repels liquid contacting the hydrophobic coating. The hydrophobic portion of the interior surface enables light to refract through the hydrophobic portion and the wall in the same manner as is the case when the hydrophobic portion is not present on the interior surface.

CROSS-REFERENCE

The present application is a Continuation application of U.S. patentapplication Ser. No. 15/715,791 filed Sep. 26, 2017, now U.S. Pat. No.10,314,972 which is also a Continuation application of U.S. patentapplication Ser. No. 15/154,048 filed May 13, 2016, now U.S. Pat. No.9,801,996 which is also a Continuation application of U.S. patentapplication Ser. No. 13/828,859 filed Mar. 14, 2013, now U.S. Pat. No.9,352,081, which is incorporated herein by reference.

BACKGROUND

The present disclosure relates to a drip chamber, for an infusion tube,with an interior surface having a hydrophobic surface, in particular, ahydrophobic surface with optical properties enabling optical imagingthrough the hydrophobic surface.

FIG. 5 is a pictorial representation of prior art drip chamber 200 withspurious droplets 202 clinging to interior surface 204 of the dripchamber. For purposes of illustration, FIG. 5 is presented as a linedrawing. During operation of drip chamber 200, when fluids are flowingthrough the drip chamber, droplets of fluid, such as droplets 202, formon the interior surface of the drip chamber due to splashing of thefluid, or by evaporation of the fluid from the reservoir at the bottomof the drip chamber and subsequent condensation of the fluid on theinterior surface. Droplets 202 can cause substantial problems withrespect to imaging the drip chamber, for example, imaging drop 206pendant from drip tube 208. For example, the droplets can cause errorsin the measurement of the size of drop 206. Droplets such as droplets202 in other portions of the drip tube, for example in the vicinity of ameniscus, can cause similar problems, such as errors in measuring aposition/level of the meniscus.

SUMMARY

According to aspects illustrated herein, there is provided a dripchamber for an infusion tube, including: a first end including a driptube; a second end including an exit port; and a wall connecting thefirst and second ends and including an interior surface with ahydrophobic portion. The drip chamber includes a space enclosed by theinterior wall and the first and second ends. The hydrophobic portion ofthe interior surface repels liquid contacting the hydrophobic coating.The hydrophobic portion of the interior surface enables light to refractthrough the hydrophobic portion and the wall in the same manner as isthe case when the hydrophobic portion is not present on the interiorsurface.

According to aspects illustrated herein, there is provided a method offabricating a drip chamber for an infusion tube, including: forming afirst end including a drip tube; forming a second end including an exitport; forming a wall connecting the first and second ends and includingan interior surface; forming a hydrophobic portion on the interiorsurface; and enclosing a space with the interior surface and the firstand second ends. The hydrophobic portion of the interior surface repelsliquid contacting the hydrophobic coating. The hydrophobic portion ofthe interior surface enables light to refract through the hydrophobicportion and the wall in the same manner as is the case when thehydrophobic portion is not present on the interior surface.

According to aspects illustrated herein, there is provided an opticalimaging system for an infusion tube, including: a drip chamber with: afirst portion with a drip tube; a second portion with an exit port; athird portion located between the first and second portions; and a wallconnecting the first and second ends and including an interior surfacewith a portion having a hydrophobic portion of the interior surfacealigned with at least one of the first or third portions in a directionorthogonal to a longitudinal axis for the drip chamber passing throughthe first and second ends. The system includes: at least one lightsource for emitting light; and an optics system including at least onelens for receiving and transmitting the light transmitted through thehydrophobic portion of the interior surface and the at least one of thefirst or third portions, and an image sensor for receiving thetransmitted light from the at least one lens and generating andtransmitting data characterizing the transmitted light from the at leastone lens. The system includes a memory element configured to storecomputer readable instructions and at least one specially programmedprocessor configured to execute the computer readable instructions togenerate, using the data, at least one image of the at least one of thefirst or third portions. The hydrophobic portion of the interior surfacerepels liquid contacting the hydrophobic portion of the interiorsurface. The hydrophobic portion of the interior surface enables thelight to pass through the hydrophobic portion of the interior surfacewithout scattering.

According to aspects illustrated herein, there is provided a method ofimaging an infusion tube having a drip chamber including a first portionwith a drip tube, a second portion with an exit port, a third portionlocated between the first and second portions, and a wall connecting thefirst and second ends and including an interior surface with a portionhaving a hydrophobic portion of the interior surface aligned with atleast one of the first or third portions in a direction orthogonal to alongitudinal axis for the drip chamber passing through the first andsecond ends, the method includes: repelling liquid contacting thehydrophobic portion of the interior surface; emitting, using at least atleast one light source, light; transmitting the light through thehydrophobic portion of the interior surface and at least one of thefirst or third portions without scattering the light; receiving, usingat least one lens, the light transmitted through the hydrophobic portionof the interior surface and the at least one of the first or thirdportions; transmitting, through the at least one lens, the lighttransmitted through the hydrophobic portion of the interior surface andthe at least one of the first or third portions; receiving, using animage sensor, the transmitted light from the at least one lens;generating and transmitting, using the image sensor, data characterizingthe transmitted light from the at least one lens; storing computerreadable instructions in a memory element; and executing the computerreadable instructions, using at least one specially programmed processorand the data, to generate at least one image of the at least one of thefirst or third portions.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are disclosed, by way of example only, withreference to the accompanying schematic drawings in which correspondingreference symbols indicate corresponding parts, in which:

FIG. 1 is a schematic representation of an optical imaging systemincluding a drip chamber with a hydrophobic portion of the interiorsurface;

FIG. 2 is a cross-section view generally along line 2-2 in FIG. 1;

FIG. 3 is a cross-section view generally along line 3-3 in FIG. 1;

FIG. 4 is a picture illustrating example periodic structure for ahydrophobic portion of the interior surface; and

FIG. 5 is a pictorial representation of a prior art drip chamber withspurious droplets clinging to an interior surface of the drip chamber.

DETAILED DESCRIPTION

At the outset, it should be appreciated that like drawing numbers ondifferent drawing views identify identical, or functionally similar,structural elements of the disclosure. It is to be understood that thedisclosure as claimed is not limited to the disclosed aspects.

Furthermore, it is understood that this disclosure is not limited to theparticular methodology, materials and modifications described and assuch may, of course, vary. It is also understood that the terminologyused herein is for the purpose of describing particular aspects only,and is not intended to limit the scope of the present disclosure.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which this disclosure belongs. It should be understood thatany methods, devices or materials similar or equivalent to those can beused in the practice or testing of the disclosure.

FIG. 1 is a schematic representation of optical imaging system 100including drip chamber 102 with a hydrophobic portion of the interiorsurface.

FIG. 2 is a cross-section of drip chamber 102 generally along line 2-2in FIG. 1.

FIG. 3 is a cross-section of drip chamber 102 generally along line 3-3in FIG. 1.

The following should be viewed in light of FIGS. 1-3. Drip chamber 102for infusion tube 104 includes end 106 with drip tube 108 and end 110including exit port 112. Drip chamber 102 includes wall 114 connectingends 106 and 110. Wall 114 includes interior surface 116 having at leastone hydrophobic portion 118. It should be understood that FIGS. 2 and 3are not scale drawings and that the thickness of portion 118 in FIGS. 2and 3 is exaggerated for purposes of illustration. Wall 114 includesspace 122 enclosed by interior surface 116 and ends 106 and 110.Hydrophobic portion 118 repels liquid 124 in drip chamber 102.Hydrophobic portion 118 is optically clear and enables light to refractthrough hydrophobic portion 118 and wall 114 in the same manner as isthe case when the hydrophobic portion 118 is not present on interiorsurface 116, as further described below. Stated otherwise, hydrophobicportion 118 enables direct mapping of light 126A and 126B, passingthrough portion 118, from a point, such as pendant drop 128 on drip tube108, within drip chamber 102, to a point on an image (described below)of the point in drip chamber 102. That is, hydrophobic portion 118enables points illuminated in drip chamber 102 by the emitted light tobe accurately imaged using light transmitted through hydrophobic portion118. In an example embodiment, infusion tube 104 includes output tube130.

In an example embodiment, hydrophobic portion 118 is aligned withportion 132 of drip chamber 102, including end 106, in direction Rorthogonal to longitudinal axis LA for drip chamber 102. Axis LA passesthrough ends 106 and 110. Portion 132 is sized to include drop 128pendant from end 134 of drip tube 108. Thus, hydrophobic portion 118enables accurate optical imaging of pendant drop 128 by preventing thedroplets described above from forming on portion 118, while enablingundistorted light transmission. Optical imaging of drop(s) 128 can beused to control flow of liquid 124 through drip chamber 102 or can beused to detect alarm conditions, such as an empty bag alarm for bag 136supplying liquid 124 to drip chamber 102.

In an example embodiment, hydrophobic portion 118 is aligned withportion 138 of drip chamber 102, between ends 106 and 110, in directionR. In an example embodiment, portion 138 is located to include meniscus140 for liquid 124 in drip chamber 102. Thus, hydrophobic portion 118enables accurate optical imaging of meniscus 140 by preventing thedroplets described above from forming on portion 118, while enablingundistorted light transmission. Optical imaging of meniscus 140 can beused to determine a level of liquid 124 in chamber 102, which can beused to control flow of liquid 124 through drip chamber 102. In anexample embodiment, hydrophobic portion 118 covers both portions 132 and138. In an example embodiment, hydrophobic portion 118 covers more thanportions 132 and 138. In an example embodiment, hydrophobic portion 118covers the entirety of surface 116 between ends 106 or 110.

In an example embodiment, a contact angle for liquid 124 in contact withhydrophobic portion 118 is between 90 and 180 degrees. As is understoodin the art, the contact angle is an angle, measured through liquid, suchas liquid 124, where a liquid interface contacts a hydrophobic material,such as hydrophobic portion 118. The angle range described above enablesrobust repelling of liquid from portion 118.

FIG. 4 is a picture illustrating example periodic structure forhydrophobic portion 118. In an example embodiment, hydrophobic portion118 includes a plurality of periodic structures. In an exampleembodiment, hydrophobic portion 118 includes a plurality of structuresin a non-periodic configuration.

In an example embodiment, hydrophobic portion 118 is formed of a samepiece of material forming wall 114, that is, hydrophobic portion 118 isintegral to material forming wall 114. For example, interior surface 116is operated upon in some fashion to create hydrophobic portion 118. Asan example, interior surface 116 can be molded using injection molding,injection-compression molding, compression molding, or embossing, toform hydrophobic portion 118. Hydrophobic portion 118 can be formed bymodifying surface 116 with surface modification technologies such asplasma.

In an example embodiment, hydrophobic portion 118 is formed of amaterial 141, separate from material 143 forming wall 114. Material 141is adhered to material 143. Material 141 can include a polymer, such as,but not limited to acrylic, polystyrene, polycarbonate, vinyl or amixture of polymers.

In an example embodiment, hydrophobic portion 118 is a coating free ofmicrostructure, such as wax, polytetrafluoroethylene, or water repellentglass powder, applied to surface 116.

In an example embodiment, the material forming hydrophobic portion 118is fluorinated to improve hydrophobic properties.

In addition to the desirable optical clarity characteristics notedabove, in an example embodiment, hydrophobic portion 118 reflects lessthan one percent of light incident upon hydrophobic portion 118. Thus,the vast majority of light incident upon hydrophobic portion 118 istransmitted through wall 114, enabling high resolution and accurateimagery, and virtually eliminating fresnel reflectance or glare.

In an example embodiment, hydrophobic portion 118 repels: inorganicliquid such as water; organic liquid such as alcohols, proteins, andoils; a solution of an inorganic liquid with a dissolved organicsubstance; a solution of an inorganic liquid with a dissolved inorganicsubstance; a solution of an organic liquid with a dissolved organicsubstance; and, a solution of an organic liquid with a dissolvedinorganic substance.

The following provides further exemplary detail regarding hydrophobicportion 118. Hydrophobic portion 118 can be a one-dimensional or atwo-dimensional array of microstructure. Hydrophobic portion 118 canhave random or stochastic structure. The depth of hydrophobic portion118 can be between 50 nm and 500 nm. The pitch of an array ofhydrophobic microstructure for hydrophobic portion 118 can be between 50nm and 500 nm.

In an example embodiment, when hydrophobic portion 118 ismicrostructured, the microstructure can have a cross-sectional profilethat is substantially triangular, partially elliptical, parabolic, orhair-like with an indeterminate profile. In an example embodiment,surface 116 is transparent to light 126A and 126B, but is tinted forvisual differentiation by the naked eye. In an example embodiment, themicrostructure is oriented substantially orthogonal to wall 114. In anexample, the microstructure is oriented at an acute angle with respectto wall 114, for example, angled toward end 106 or toward end 110.

As shown in FIG. 1, optical imaging system 100 can be used with infusiontube 104 including drip chamber 102. In an example embodiment. system100 includes at least one Hat source 142, for example sources 142A and142B for emitting light 126A and 126B. respectively, and system 100includes optics system 144. System 144 includes at least one lens 148,for example, lenses 148A and 148B, and at least one image sensor 150,for example, sensors 150A and 150B. Lenses 148A and 148B are forreceiving and transmitting light 126A and 126B transmitted throughhydrophobic portion 118 of the interior surface and portions 132 and138, respectively. Sensors 150A and 150B receive the transmitted light126A and 126B from lenses 148A and 148B respectively, and generate andtransmit data 152A and 152B characterizing transmitted light 126A and126B from lenses 148A and 148B, respectively. System 100 includes atleast one specially programmed processor 156 configured to generateimages 158A and 158B of portions 132 and 138, respectively. System 100includes memory element 160 configured to store computer executableinstructions 162. Processor 156 is configured to execute instructions162 to generate images 158A and 158B. Note that system can include onlylight source 142A, lens 148A, and sensor 150A, and not light source 142Blens 148B. and sensor 150B, or light source 142B, lens 148B. and sensor150B and not light source 142A lens 148A. and sensor 150A.

As noted above, image 158A can include pendant drop 128 and image 158Acan be used to control flow through infusion tube 102 or to monitor foralarm conditions. As noted above, image 158B can include meniscus 140and image 158B can be used to monitor the level of meniscus 140 in dripchamber 102.

Advantageously, hydrophobic portion 118 enables more accurate andprecise images 158A and 158B by eliminating spurious droplets, notedabove, clinging to interior surface 116, while enabling diffused lighttransmission. For example, a rendering of pendant drop 128 in image 158Ais not cluttered or obscured by spurious droplets clinging to surface116 in portion 130, while at the same time benefiting from diffusedtransmission of the light used to form image 158A. For example, theboundary of meniscus 140 is not obscured or distorted by spuriousdroplets clinging to surface 116 in portion 138 between meniscus 140 andportion 130, while at the same time benefiting from diffusedtransmission of the light used to form image 158B.

It will be appreciated that various of the above-disclosed and otherfeatures and functions, or alternatives thereof, may be desirablycombined into many other different systems or applications. Variouspresently unforeseen or unanticipated alternatives, modifications,variations, or improvements therein may be subsequently made by thoseskilled in the art which are also intended to be encompassed by thefollowing claims.

What is claimed is:
 1. A drip chamber for an infusion tube, comprising:a wall extending between a first end and a second end, the wallenclosing a space defined by an interior surface of the wall, theinterior surface including a hydrophobic portion configured to repelliquid contacting the hydrophobic portion, wherein the hydrophobicportion is configured for refracting substantially all light beingtransmitted through the wall, and eliminating substantially allreflectance or glare formed on the wall, and wherein the hydrophobicportion of the interior surface enables direct mapping of the lightpassing through the hydrophobic portion of the interior surface from apoint within the drip chamber to a point on an image of the point in thedrip chamber.
 2. The drip chamber of claim 1, wherein a longitudinalaxis for the drip chamber passes through the first and second ends ofthe drip chamber and the hydrophobic portion of the interior surface isaligned with the first end of the drip chamber in a direction orthogonalto the longitudinal axis for the drip chamber.
 3. The drip chamber ofclaim 1, wherein when the drip chamber includes fluid disposed in thedrip chamber, the hydrophobic portion of the interior surface is alignedwith a meniscus for the fluid in a direction orthogonal to alongitudinal axis for the drip chamber passing through the first andsecond ends of the drip chamber.
 4. The drip chamber of claim 1,wherein: a contact angle for a liquid in contact with the hydrophobicportion of the interior surface is between 90 and 180 degrees; and, thecontact angle is an angle, measured through the liquid, where a liquidinterface contacts the hydrophobic portion of the interior surface. 5.The drip chamber of claim 1, wherein the hydrophobic portion of theinterior surface includes a first plurality of periodic structures. 6.The drip chamber of claim 1, wherein the hydrophobic portion of theinterior surface includes a first plurality of structures in anon-periodic configuration.
 7. The drip chamber of claim 1, wherein thehydrophobic portion of the interior surface is formed of a same piece ofmaterial forming the wall.
 8. The drip chamber of claim 1, wherein: thehydrophobic portion of the interior surface is formed of a firstmaterial, separate from a second material forming the wall; and, thefirst material is adhered to the second material.
 9. The drip chamber ofclaim 1, wherein the hydrophobic portion of the interior surfacereflects less than one tenth of one percent of light incident upon thehydrophobic portion of the interior surface.
 10. The drip chamber ofclaim 1, wherein the hydrophobic portion of the interior surface repels:a first inorganic liquid including water; a first organic liquidincluding alcohols, proteins, or oils; a solution of a second inorganicliquid with a dissolved first inorganic substance; a solution of a thirdinorganic liquid with a dissolved first organic substance; a solution ofa second organic liquid with a dissolved second inorganic substance; or,a solution of a third organic liquid with a dissolved second organicsubstance.
 11. A method of forming a drip chamber for an infusion tube,comprising: enclosing a space defined by an interior surface of a wall,the space extending between a first end and a second end and theinterior surface including a hydrophobic portion, wherein: thehydrophobic portion of the interior surface repels liquid contacting thehydrophobic portion; and, the hydrophobic portion of the interiorsurface is configured for refracting substantially all light beingtransmitted through the wall, and eliminates substantially allreflectance or glare formed on the wall, and, wherein the hydrophobicportion of the interior surface enables direct mapping of the lightpassing through the hydrophobic portion of the interior surface from apoint within the drip chamber to a point on an image of the point in thedrip chamber.